of course, the congressman is the son of the famed civil rights activist jesse jackson. earlier this month, he easily won re-election for a ninth term to the house of representatives. despite the fact that he essentially disappeared in june. since then, he has been in and out of the mayo clinic receiving treatment for bipolar disorder and gastrointestinal issues. the congressman mentioned those health problems in the letter of resignation that he submitted today to house speaker john boehner's office. but he also wrote, quoting here: i am aware of the ongoing federal investigation into my activities and i am doing my best to address the situation sonsably, cooperate with the investigators and accept responsibility for my mistakes for they are my mistakes and mine alone. mike tobin is live for us in chicago with more. mike, did this come as a shock to anyone? >> no. for the reasons you just mentioned, no one was surprised that the congressman stepped down. in fact it was a question of when it would happen. however, fellow politicians and friends here in chicago were quick